101 results about "Discrete element model" patented technology

The invention discloses a coal rock seepage-stress coupling simulation calculation method, which belongs to the technical field of geotechnical engineering numerical simulation, and comprises the following steps: carrying out gray threshold division on a coal rock sample CT scanning result to obtain a coal rock CT section; identifying particle position information in a coal rock CT section, and establishing a coal rock refined discrete element model; performing mechanical constitutive parameter calibration on the coal rock refined discrete element model; and on the basis of the coal rock refined discrete element model subjected to constitutive parameter calibration, establishing a fluid grid, setting model parameters, and carrying out seepage-stress coupling calculation. According to the method, the real form, size, spatial distribution and mutual inlaying relation of the mineral components in the coal rock can be accurately captured, and the most real basis is provided for accurate simulation of subsequent mechanical behaviors.

The invention is suitable for the technical field of plant simulation modeling, and provides a corn ear general modeling method, which comprises the following steps: determining composition unit ball particles according to an ear structure; segmenting based on the shape and arrangement of the grains; obtaining morphological representation parameters and fitting a function relationship; geometric model parameters are calculated; universal modeling of the horse-tooth-shaped and fan-shaped grains is achieved; calculating the coordinates of spherical particles by adopting a combined ball method; filling the contour with spherical particles through rotation and translation transformation, and establishing a geometric model; and completing discrete element model construction in combination with mechanical model parameters. The method has the advantages of being high in universality, high in modeling precision, good in flexibility and the like, calculation and parameter calibration processes can be simplified, group model analysis is supported, and a reliable basis is provided for simulation of behaviors such as threshing and breaking of corn ears.

The application discloses a TBM cutter rock breaking efficiency optimization method and control system based on penetration and cutter spacing coupling, comprising: constructing a double-cutter rock breaking linear cutting numerical model, wherein the double-cutter rock breaking linear cutting numerical model is a discrete element model; simulating the double-cutter rock breaking linear cutting numerical model, and calculating the rock breaking specific energy consumption under the cutting action of different penetrations and cutter spacings according to the simulation result, wherein the rock breaking specific energy consumption is calculated according to mechanical parameters and lithology parameters; fitting the rock breaking specific energy consumption under different penetrations, and obtaining an optimal cutter spacing according to the fitting result, calculating the cutter spacing and penetration ratio according to the optimal cutter spacing; obtaining an optimal penetration and cutter spacing combination according to the trend of the cutter spacing and penetration ratio; and adjusting the penetration and cutter spacing of the TBM cutter according to the optimal penetration and cutter spacing combination, so as to improve the rock breaking efficiency and construction speed of the TBM.

The application discloses a soil deep loosening simulation method based on DEM-FEM bidirectional coupling. The method comprises the following steps: establishing a soil discrete element model and a deep loosening tool finite element model; using the discrete element DEM simulation to analyze the influence law of soil characteristic parameters and deep loosening tool motion parameters on soil deep loosening effect and deep loosening tool working resistance; changing the soil characteristic parameters and deep loosening tool motion parameters, and calculating the information such as soil deep loosening particle mixing degree, deep loosening tool working efficiency and working resistance under different variables; analyzing the influence law of the working resistance obtained from the DEM on the deep loosening tool structure through the finite element FEM analysis, changing the soil structure parameters and deep loosening tool structure parameters, and counting the statics and dynamics analysis results under different variables; simulating through the DEM-FEM bidirectional coupling, analyzing the soil deep loosening mechanism of the deep loosening tool, and obtaining the parameter and structure optimization results. Compared with the prior art, the application can effectively reduce resistance and consumption, and improve working efficiency.

The invention discloses an abrasive water jet rock breaking simulation method based on a DEM-CFD coupling method. Establishing an EBPM bonded rock mass discrete element model through a discrete element DEM, and calibrating mesoscopic parameters through a virtual mechanical test; simulating a water-abrasive two-phase flow through fluid dynamics CFD, and adopting a Gidaspow drag force model; the DEM-CFD bidirectional interface realizes real-time coupling; carrying out post-treatment to extract an erosion morphology and a crack network; the method can effectively simulate the rock mass fracture process and the large deformation behavior in the water jet rock breaking process and reveal rock mass damage evolution from the microscopic scale, and can be widely applied to research of water jet assisted rock breaking in the fields of civil engineering, mining, petroleum energy, marine resources and the like.

The application discloses a kind of discrete element modeling methods of multi-layer interpenetrating shear mixing drill and soil body, comprising: S1, the design parameter of multi-layer interpenetrating shear mixing drill is obtained, design parameter includes the pitch of blade, inclination, shape, size and quantity;Multi-layer interpenetrating shear mixing drill includes inner drill rod, multiple pairs of inner blades and outer frame arranged on inner drill rod;The outer frame includes multiple pairs of outer blades, two side plates and a collar arranged at intervals, and each pair of outer blades and each pair of inner blades are arranged at intervals;S2, the modeling of multi-layer interpenetrating shear mixing drill is carried out to obtain drill model;S3, establish soil model, import drill model, distribute contact model, and construct the coupling discrete element model between multi-layer interpenetrating shear mixing drill and soil particles;S4, simulation is carried out using coupling discrete element model, and quantitative analysis is carried out on mixing effect according to simulation result.The coupling discrete element model constructed by the above method has reliability and engineering applicability, and provides quantifiable basis for drill structure optimization.

The invention belongs to the technical field of lithium batteries, and relates to a material particle size grading optimization method and system based on a genetic algorithm and discrete element simulation. The method comprises the following steps: carrying out particle size distribution test on a material to be optimized to obtain a particle size distribution result as an optimizable particle size range; carrying out three-component peak separation on the obtained particle size distribution result, and approximately representing the particle size distribution of the material through three-component spherical particles; optimizing the stacking density of the three-component spherical particles in an optimizable particle size range by utilizing a genetic algorithm, and enabling the optimized stacking density of the three-component spherical particles to be approximate to the compaction density of the three-component spherical particles; obtaining physical property data of the material; and carrying out simulation verification on the compaction density of the three-component spherical particles obtained by optimization by using a discrete element model according to physical property data of a material. According to the method, optimization design is carried out on the particle size of the material based on discrete element analog simulation and a genetic optimization algorithm, and the large and small particle gradation of the high-compaction-density material can be rapidly screened.

The application relates to a kind of asphalt pavement road surface texture modeling methods based on three-dimensional discrete element model, comprising: step S1: selecting representative coarse aggregate from the aggregate constituting asphalt pavement wearing course, obtaining the surface topography as the first real aggregate profile model after scanning each selected coarse aggregate;Step S2: based on the first real aggregate profile model, the three-dimensional discrete element model of asphalt mixture is constructed as the asphalt pavement model, the micro-mechanical properties between the aggregate particles in the asphalt pavement model are given, and the texture parameters and the inter-particle porosity of the asphalt pavement model are calculated;Step S3: the surface texture parameters and the inter-particle porosity of the real asphalt pavement with the same aggregate and gradation are calculated, and compared with the texture parameters and the inter-particle porosity of the asphalt pavement model, if the error is too large, then return to step S2 to adjust the micro-mechanical properties between the aggregate particles in the asphalt pavement model.Compared with the prior art, the application can accurately simulate pavement texture and establish the corresponding relationship between wearing course texture and skeleton.

The invention belongs to the technical field of oil and gas field development engineering, and particularly relates to a conglomerate reservoir horizontal well perforation completion discrete element modeling method. The method comprises the following steps: extracting a conglomerate contour of a target area; taking the conglomerate contour of the extracted target area as a constraint boundary, generating a plurality of discrete small ball particles to fill the interior of the conglomerate contour and the residual matrix area, and further generating a conglomerate discrete element model; the method comprises the following steps: acquiring field perforation well completion data of a horizontal well in a target area, and converting the field perforation data to generate a horizontal well shaft wall unit containing perforations; the field perforation completion data at least comprise perforation depth, perforation aperture, perforation density, wellbore diameter and wellbore length parameters. Through the conglomerate reservoir perforation horizontal well fracturing simulation technology, the limitation of a traditional homogeneous model is broken through, and accurate reduction of the heterogeneity of a real reservoir is achieved.

The invention discloses a pavement load analysis method based on discrete elements and a related device, and the method comprises the steps: collecting geometric features and material parameters of an asphalt pavement, and constructing a discrete element model; based on the constructed discrete element model, creating a rigid load plate in the target area, and simulating a tire-road contact surface; a target load is applied through a rigid load plate, displacement field distribution under the action of the load is calculated based on a discrete element model subjected to the load, and settlement response analysis is achieved. The discrete element model of the asphalt pavement is established on a physical scale closer to reality, and interlayer and particle contact conditions are flexibly defined through fine unit division; on the premise of reducing the cost, the transmission path and the distribution characteristic of the dynamic load in an actual pavement structure and the complex internal mechanical response caused by the transmission path and the distribution characteristic can be more accurately captured, and powerful support is provided for comprehensive improvement of scientificity, reliability and precision of pavement engineering design and accurate prediction of pavement diseases.

The application discloses a kind of long approach in paste flow slope angle prediction method, belong to filling technical field, solve the prediction of filling slope angle in prior art is based on experience formula or static homogeneous model, unable to consider the influence of waste rock dynamic settlement on slurry flow resistance and slope form Problem, the method includes based on paste raw material basic parameter construction paste similarity model, based on range analysis combined with interaction analysis influencing factor on the influence degree of flow slope angle, convert flow slope angle calculation model into slope angle satisfaction function, obtain slope angle optimal filling parameter;The present application can comprehensively study the influence of multiple influencing factors and their interaction on paste flow slope angle through the pre-design and implementation of orthogonal experiment scheme, avoids the one-sidedness that single factor analysis may bring, makes the influence law obtained more comprehensive and in-depth, and is different from the homogeneous flow model or simplified discrete element model that the existing numerical simulation method is mostly used.

The invention relates to a numerical simulation method and device for tunnel mud burst and water burst disasters. The method comprises the following steps: acquiring a three-dimensional discrete element model of a target area according to geological information of the target area, simulating a mud burst water gushing disaster process caused by tunnel excavation by utilizing the three-dimensional discrete element model based on tunnel information, obtaining a numerical simulation result of the mud burst water gushing disaster, adjusting an angle corresponding to a tunnel crossing fault area in the tunnel information, and obtaining a numerical simulation result of the mud burst water gushing disaster. And obtaining numerical simulation results of the mud burst and water burst disasters under different tunnel information. By adopting the method, the numerical simulation result of the mud burst water gushing disaster simulated by the three-dimensional discrete element model can be obtained at the angles corresponding to different tunnel crossing fault areas, the occurrence process of the tunnel mud burst water gushing can be sufficiently described subsequently, and the accuracy of the simulation result is improved.

The invention discloses a three-dimensional random field-based rockfill material space variability discrete element simulation method. The method specifically comprises the following steps of: 1, constructing a triaxial test discrete element model and determining related parameters; step 2, generating a three-dimensional random field based on Karhunen-Loeve expansion; and step 3, random interpolation and assignment of particle contact parameters. Aiming at the technical defect that the real mechanical behavior of the rockfill material cannot be accurately reflected due to the fact that homogeneous hypothesis, two-dimensional modeling and continuous medium analysis are generally adopted in the prior art, the method comprises the following steps: constructing a three-dimensional random field of the rockfill material and introducing a discrete element particle system; more reasonable and more practical description of rockfill material space variability, macroscopic mechanical characteristics and mesoscopic mechanism deformation is realized.

The application discloses a modeling method of a two-dimensional ballast particle discrete element model and a modeling method of a two-dimensional sleeper-track bed-substrate discrete element model containing sand, and the modeling method of the two-dimensional ballast particle discrete element model comprises the following steps: extracting an outer contour of a ballast particle; determining an inner contour of the ballast particle according to the outer contour; filling the inner contour of the ballast particle with the largest inscribed circle disc until a preset standard is reached; filling a circle of inscribed circle discs between the inner contour and the outer contour of the ballast particle; exporting the radius and position coordinates of each disc after the filling is completed; and establishing a periodic boundary, and establishing a ballast particle discrete element model template according to the radius and coordinates of each disc. The two-dimensional ballast particle discrete element model provided by the application solves the contradiction between model precision and calculation cost, and the modeling method of the two-dimensional sleeper-track bed-substrate discrete element model containing sand can realize rapid filling of fine particles in a track bed ballast gap, and other dirty track beds can be quickly established from the model filled with fine particles once.

A vehicle sand rolling simulation method, device, equipment and readable storage medium, comprising: constructing a whole vehicle simulation model and a discrete element model representing sand particles, and determining key contact areas and non-key contact areas in the whole vehicle simulation model; setting interaction parameters, including sand particle interaction parameters and interaction parameters between the discrete element model and the whole vehicle simulation model, wherein the contact relationship between the vehicle and the sand particles is defined by a discrete element and structure surface coupling mode for the key contact areas, and the acting force is calculated based on the geometric boundary of the sand particles; constructing a whole vehicle sand rolling simulation model according to the discrete element model, the whole vehicle simulation model and the interaction parameters; and performing vehicle sand rolling simulation based on the whole vehicle sand rolling simulation model. The whole vehicle is divided into key contact areas and non-key contact areas in the application, the contact relationship of the key areas is defined by a discrete element and structure surface coupling mode, the simulation fidelity is ensured, and the balance between calculation efficiency and simulation accuracy is realized.

The invention relates to the technical field of rock mass stress field inversion, in particular to a stratified rock mass discrete element model crustal stress field inversion method based on deep learning, which comprises the following steps: acquiring a main control surface patch node extraction normal change sequence, comparing attitude path positioning direction mutation regions, analyzing included angle change to generate a construction path trend structural body, and calculating the stress field of the stratified rock mass. And node information is extracted to establish a structural path combination input primitive set, direction attributes are written to form a crack direction embedded tag group, and a constructed inversion sequence is input into a preset deep learning model to output a crustal stress inversion tensor field result. According to the method, the node direction change is extracted, mutation fragments are identified, spatial paths consistent in direction are constructed, a node sequence is generated in combination with the principal stress direction and the construction trend, coordinates, direction and construction information are fused to construct a spatial label group, an inversion input sequence is embedded, and the structural path and stress distribution relation is associated. The space matching between the path identification capability and the tensile stress direction is improved, and the distribution continuity and inversion stability of the tensor result in the structure are enhanced.

The invention discloses a lunar soil coring dynamic process simulation method based on FEM-SPH coupling, and the method comprises the steps: building a three-dimensional geometric model of real lunar soil particles based on the scanning data of the real lunar soil particles; establishing a lunar soil discrete element model based on the three-dimensional geometric model; performing a virtual mechanical test on the lunar soil discrete element model, and calibrating lunar soil macromechanical parameters; constructing a drilling tool finite element model, and defining a contact relation between the drilling tool finite element model and the lunar soil; based on the calibrated lunar soil macromechanical parameters, establishing an SPH particle model of the lunar soil; coupling the drilling tool finite element model and the SPH particle model, and performing lunar soil coring dynamic process simulation based on the contact relationship to obtain bedding information disturbance and drilling tool sampling rate results. According to the method, accurate simulation of the dynamic process of lunar soil coring is achieved, and a sampling rate and bedding information disturbance quantitative basis is provided for optimization of drilling tool parameters and drilling working conditions.

The invention discloses a method for constructing a finite discrete element model of a composite material based on a micrometer indentation test. The method comprises the following steps: S1, calculating the reduction modulus Er and hardness H of each indentation point representing the area according to a load-displacement curve obtained by the micrometer indentation test; s2, constructing a data matrix, dividing a weak-phase material, a middle-phase material and a strong-phase material according to micro-mechanical properties of the composite material, and then calculating an elastic parameter, a plastic parameter and brittleness of the phase according to an indentation curve based on a classification result of a K-means algorithm; s3, carrying out inversion calculation on the basis of the obtained materials of each phase to obtain an elastic parameter, a plastic parameter and a brittleness parameter of the microscale of each material of each phase, and constructing a micron indentation model of the single-phase material on the basis of the parameters; s4, constructing a micron indentation model of the large-size multi-phase material; and S5, completing the construction of the model. The method has the advantages that the simulation result is more practical, the precision is high, and the data reliability is high.

The invention discloses an asphalt mixture freeze thawing discrete element modeling method. The method comprises the following steps: S1, constructing an asphalt mixture initial discrete element model; s2, adding a contact model among model particles of the initial discrete element model of the asphalt mixture constructed in S1, and calibrating mesoscopic parameters according to indoor experimental data to obtain a complete sample model; s3, compiling a freeze-thaw cycle subprogram based on a water-ice phase change coupling expansion method to perform freeze-thaw cycle simulation on the sample model obtained in S2; and S4, performing freeze-thaw cycle simulation on the sample model obtained in S2 under different working conditions based on the freeze-thaw cycle subprogram compiled in S3. The frost heaving stress is simulated through a water-ice phase change coupling expansion method, and a way is provided for researching a frost heaving damage mechanism of the asphalt mixture; flexible setting of multiple parameters such as freezing and thawing temperature, rate and temperature difference is supported through a cosine temperature formula, and refined simulation is achieved; the freezing and thawing cycle result is high in precision, and the design of the asphalt pavement in the cold region can be guided.

The invention relates to the technical field of geotechnical engineering, and particularly discloses a full-surface strain analysis method and device based on a discrete element model, and the method comprises the steps: constructing the discrete element model of a target region, and calculating the displacement data of each particle in the target region through the discrete element model when the discrete element model deforms; dividing the target area into a plurality of grids, and calculating the displacement data of each grid datum point according to the displacement data of the particles in each grid; constructing a continuous displacement field according to the displacement data of each grid datum point, and calculating a displacement gradient tensor of each grid datum point; calculating a Green Lagrange strain tensor according to the displacement gradient tensor; calculating the maximum principal strain of each grid according to the Green Lagrange strain tensor; calculating a non-uniform coefficient of the target area according to the standard deviation and the average value of the maximum principal strain of each grid in the target area; and determining an instability risk judgment result of the target area according to the non-uniform coefficient. According to the method, a stable strain result can be obtained under a relatively large deformation situation.

The present application relates to the field of frozen soil subgrade structure calculation, in particular to a subgrade analysis calculation method considering local degradation of permafrost subgrade. The present application assumes that the diameter D and height H of the pavement settlement area are the target settlement, assumes the position, size and degradation degree of the degradation area, carries out numerical analysis through finite element or discrete element, obtains the post-construction pavement settlement, compares the difference between the simulated post-construction pavement settlement and the target settlement, randomly changes or changes the position, size and degradation degree of the degradation area according to the rule, repeatedly tries and calculates, and finally obtains the foundation degradation position, size and degradation degree which almost coincide with the target settlement. The degradation areas determined by a plurality of sets of degradation area parameters are established in the finite element or discrete element model, are combined with other load calculation conditions of the pavement load respectively, the corresponding subgrade structure load effect of each degradation area is calculated, and the most unfavorable value or the average value is taken to design or evaluate the subgrade strength, deformation and stability.

The invention discloses a discrete element method for representing elastic-plastic fiber deformation, and belongs to the field of computational mechanics and numerical simulation. According to the method, to-be-analyzed elastic-plastic fibers are divided into ideal elastic-plastic fibers and damaged elastic-plastic fibers, for different types of elastic-plastic fibers, a bonded ball model is adopted to represent fiber dynamic characteristics, and a bending moment-bending angle analysis model of elastic-plastic bonds is established by integrating cross section stress of the bonds in the fibers; and further constructing a bending moment increment model at any bending angle, and simplifying by adopting a piecewise linear method to obtain a simplified model of the elastic-plastic key bending moment-bending angle relationship, so as to obtain the deformation characteristics of the to-be-analyzed elastic-plastic fiber. According to the discrete element model capable of representing the elastic-plastic bending deformation of the fibers, accurate description and piecewise linear simplification of nonlinear mechanical behaviors of the fiber materials are achieved, and the calculation efficiency is remarkably improved while the calculation precision is guaranteed.

The invention provides an asphalt mixture mechanical property evaluation method based on discrete element numerical simulation, and relates to the technical field of road materials, and the method comprises the following steps: setting the unit radius and boundary unit radius of component particles of an asphalt mixture to be tested, adjusting the particle size distribution of the component particles and a contact model between different component particles, and calculating the mechanical property of the asphalt mixture to be tested; establishing an initial discrete element model; carrying out a semicircular bending test based on the initial discrete element model to obtain mesomechanical characteristic parameters of the to-be-tested asphalt mixture; sub-index matrixes corresponding to the damage dimension parameters, the force transmission dimension parameters and the structure dimension parameters are determined through an ideal solution sorting method, weighting is conducted on the sub-index matrixes in combination with an objective weighting method, and a comprehensive evaluation index is obtained through weighted fusion; determining the micro-mechanical properties of the to-be-tested asphalt mixture based on the comprehensive evaluation index; the sub-index matrix comprises a damage sub-index, a force transfer sub-index and a structure sub-index.

The invention provides a method for evaluating the stability of a heterogeneous soil-rock aggregate slope under a rainfall condition, and belongs to the field of civil engineering, and the method comprises the steps: S1, obtaining the basic information of a to-be-evaluated heterogeneous soil-rock aggregate slope; s2, determining an equivalent permeability coefficient of the soil-rock mixture according to the rock content and the material parameters of the soil matrix, and determining a safety coefficient standard value of stability evaluation; s3, determining a computational domain of discrete element simulation according to the geometric parameters of the slope, and obtaining an initial equilibrium state through initial equilibrium calculation; s4, setting rainfall scene parameters, and performing dynamic response simulation on the discrete element model; s5, discrete element dynamics calculation is carried out in the dynamic response simulation process, safety coefficients are calculated at multiple moments in the rainfall process, and the stability level of the slope in the rainfall scene is determined. According to the method, refined simulation and evaluation of the rainfall induced slope instability process are realized, and the accuracy of soil-rock aggregate slope stability analysis is improved.

The invention discloses a tamping stabilization operation simulation method and system under high and cold ice and snow conditions, and belongs to the technical field of maintenance and repair of ballast lines in high and cold plateau areas. The method comprises the following steps: firstly, establishing a tamping-stabilizing device collaborative multi-flexible body dynamic model based on an actual size, and constructing a track panel multi-flexible body model by combining track panel deformation and motion characteristics; then, a multi-level breakable railway ballast model is constructed by matching a low-temperature railway ballast real breaking mode, and a ballast track bed discrete element model is generated by adopting a gravity inversion compaction method; and integrating ice and snow environment parameters to construct a ballast bed multi-field coupling model, and finally forming a device-track panel-ballast bed full-system multi-field coupling model and completing operation process simulation. According to the method, the technical bottleneck that tamping stabilization operation cannot be simulated in a traditional extreme environment is broken through, the whole process and multi-field coupling action mechanism of the tamping stabilization operation under the high and cold ice and snow conditions is precisely restored, and scientific support is provided for parameter optimization, risk avoidance and safety guarantee of the tamping stabilization operation in the high and cold regions.

This invention discloses a method and apparatus for simulating the uplift process of ancient uplifts based on discrete element method (DEM) calculations. The method includes: determining the maximum slope of the fitted curve equation based on the upper boundary of the ancient uplift, thereby determining the initial overlap ratio of the particles; filling a rectangular box model of a second specified size with particles of a first specified size, ensuring the bottom particles have an initial overlap ratio, to obtain a first DEM model; determining the microscopic parameters of the granular materials of each stratum simulated using the first DEM model through biaxial compression experiments; setting the parameters of the first DEM model using the microscopic parameters of the granular materials and strata information to obtain a second DEM model; calculating the uplift vertical velocity of each particle at the bottom of the model based on the vertical velocity of the specified particles and the maximum value of the fitted curve; and simulating the uplift process of each particle at the upper boundary of the ancient uplift according to its uplift vertical velocity. This invention can simulate the uplift process of ancient uplifts with different geometric shapes.

An intelligent grouting method and related equipment for shield tunnel construction in water-rich sandy cobble strata, comprising: obtaining stratum characteristic data of the water-rich sandy cobble strata to be grouted, constructing a shield tunnel three-dimensional finite element model and a seepage potential erosion two-dimensional discrete element model of the water-rich sandy cobble strata; using the shield tunnel three-dimensional finite element model to simulate and determine the initial grouting parameters of the water-rich sandy cobble strata; using the seepage potential erosion two-dimensional discrete element model to determine the stress amplitude change value and the porosity change gradient of the water-rich sandy cobble strata under the action of groundwater seepage potential erosion, and then dividing the water-rich sandy cobble strata into multiple risk areas with different risk levels; for different risk areas, adjusting the corresponding initial grouting parameters according to different supplementary grouting adjustment strategies; and performing grouting construction processing on the corresponding risk areas according to the adjusted grouting parameters. The present application can meet the requirements of uniformity and timeliness of grouting in sandy cobble strata for shield construction.

The invention provides a tunnel geological prediction method and system integrating micro-seismic monitoring and PFC simulation, and belongs to the field of geological exploration, and the method comprises the steps: obtaining historical blasting excavation geological data and historical tunnel blasting micro-seismic information of a tunnel; constructing a geological prediction discrete element model according to historical blasting excavation geological data, and calibrating signal features of the geological prediction discrete element model through historical tunnel blasting micro-seismic information; when the tunnel face of the tunnel is blasted and excavated, real-time micro-seismic signals are collected; simulating a simulated micro-seismic signal of the tunnel face of the tunnel through the calibrated geological prediction discrete element model; comparing variation values of the simulated micro-seismic signal and the real-time micro-seismic signal, and adjusting the calibrated geological prediction discrete element model according to the variation values to obtain a geological prediction discrete element model after geological component adjustment; and predicting geological information of an area behind the tunnel face of the tunnel through the geological prediction discrete element model after geological component adjustment. According to the method, the real-time performance and accuracy of geological prediction are improved.

The invention provides a virtual measurement method and system for machining surface quality and roughness based on point cloud, and belongs to the technical field of numerical control machining simulation and digital detection. The method comprises the steps that a geometric model of a machined workpiece shape is obtained through machining process simulation; extracting three-dimensional point cloud data of the surface of the workpiece from the geometric model; performing spatial structure analysis on the point cloud data to judge a surface forming quality state; and calculating the surface roughness based on the forming quality state and the machining process parameters. According to the method, a three-dimensional discrete element model is adopted for high-precision material removal simulation, point cloud efficient analysis is achieved through a KDTree structure, a roughness calculation model is built in combination with tool geometry and motion parameters, and accurate prediction of the surface quality before machining is achieved. The problem that simulation and quality evaluation are disjointed is solved, traditional post-event detection can be replaced, trial cutting cost is reduced, and data support is provided for process optimization.

The application relates to the technical field of tailing dam safety monitoring and early warning, in particular to a tailing dam multi-field coupling discrete element catastrophe early warning method based on an energy evolution criterion. Five modules are constructed in the Fangzhizhun software: a discrete element model construction module: a non-continuous medium model of a tailing particle accumulation body is established to represent the mechanical behavior between particles; a multi-field coupling calculation module: dynamic coupling simulation of a seepage field-stress field-chemical field-temperature field is realized; an energy evolution analysis module: a real-time tracking system energy accumulation, transformation and release process is realized, and a critical feature before catastrophe is extracted; an efficient algorithm optimization module: parallel computing and a reduced model are used to improve the calculation efficiency; a dynamic early warning decision module: based on the energy criterion and monitoring data fusion, a hierarchical early warning signal is output. The method breaks through the limitation of traditional single parameter early warning such as displacement and pore water pressure, realizes accurate capture of tailing dam catastrophe precursors from the energy driving perspective, and improves the timeliness and reliability of early warning.